Well, managed to get CGI.pm updated, however I still generate files with zero size! If I have permission to create a file does it mean that I also have permission to write to that particular file?

If you can create it, you can write to it (at least on Win32 and Unix (or Unix-like) platforms).

I'm puzzled on this one. I switch my upload script from using the

  while ( <$filename> ) { ...
[download]

approach, and tried the

  while ( read($filename, $_, 1024) ) { ...
[download]

form, and both worked (as I expected they would).

Having the read() return 0 is the only thing I could see (based on what you posted) that would cause an empty file. Since CGI.pm reads and caches the incoming file first, there might be an issue with something like the filename. Can you post the HTML form that you're using to trigger the upload, and show us the filename that you're trying to upload? There might be a clue thereabouts.